Changes assembly to inlude ENTREGA1.md instead of README.md

REAMDE.md has the general information of the project. So, students
should not overwrite this file.

Now, they are instructed to write release information in the
ENTREGA1.md file.

src/main/assembly/assembly-first-release.xml

@@ -26,7 +26,7 @@
 			<outputDirectory>/</outputDirectory>
 		</file>
 		<file>
-			<source>README.md</source>
+			<source>ENTREGA1.md</source>
 			<outputDirectory>/</outputDirectory>
 		</file>
 	</files>